P0430 Chevrolet -

Question

Have code p0430 I haved replaced oxygen sensor after cat/converter drivers side and still have the same code appear. Do I have to replace both ? Thanks for your help.

Answer 1

P0430 Catalyst system low efficiency Bank 2

The 02 sensor in the front of the catalytic is the engine management sensor, which helps maintain fuel control, the 02 sensor on the rear are catalytic monitor sensor. The ECM is capable of detecting when the 02 sensor is at fault. In this case the ECM check the 02 sensor for proper operation before it codes that the catalytic is below effiency. What the ECM does is test the catalytic at least 18 times at at least 3 drive cycles. before it concludes that the catalytic is degraded. Because you have replaced the 02 sensor you have to do a oxygen sensor resistance relearn procedure. With the scan tool regardless if there is a 02 sensor code or no code, you clear the code, this reset and the ECM and it learns the 02 resistance.If you end up up replacing the catalytic convertor for this particular model. It will code a P0420 or P0430 depending on which convertor was replaced  it will take at least 100 miles to degass the internal mating at highway speed.